You don't take a day off when there's a big job - and neither does the F-Series. Day in and day out, the F-Series is on the job.
The reason is simplified maintenance and easy service. The quick access front panel facilitates routine inspection and replenishment of fluids as well as installation of additional wiring. Bulbs and fuses are also readily replaced due to the swing-out lamp housings and cartridge-type fuse box.